8 research outputs found
Amperometric and spectrophotometric determination of carbaryl in natural waters and commercial formulations
The work presented describes the development
and evaluation of two flow-injection analysis (FIA) systems
for the automated determination of carbaryl in spiked
natural waters and commercial formulations. Samples are
injected directly into the system where they are subjected
to alkaline hydrolysis thus forming 1-naphthol. This product
is readily oxidised at a glassy carbon electrode. The
electrochemical behaviour of 1-naphthol allows the development
of an FIA system with an amperometric detector
in which 1-naphthol determination, and thus measurement
of carbaryl concentration, can be performed. Linear response
over the range 1.0Ă10â7 to 1.0Ă10â5 mol Lâ1, with a
sampling rate of 80 samples hâ1, was recorded. The detection
limit was 1.0Ă10â8 mol Lâ1. Another FIA manifold was
constructed but this used a colorimetric detector. The methodology
was based on the coupling of 1-naphthol with phenylhydrazine
hydrochloride to produce a red complex which
has maximum absorbance at 495 nm. The response was
linear from 1.0Ă10â5 to 1.5Ă10â3 mol Lâ1 with a detection
limit of 1.0Ă10â6 mol Lâ1. Sample-throughput was about
60 samples hâ1. Validation of the results provided by the
two FIA methodologies was performed by comparing
them with results from a standard HPLCâUV technique.
The relative deviation was <5%. Recovery trials were also
carried out and the values obtained ranged from 97.0 to
102.0% for both methods. The repeatability (RSD, %) of
12 consecutive injections of one sample was 0.8% and
1.6% for the amperometric and colorimetric systems, respectively
Managing the Intranet: trying a new tool
A case study is described of how the Open University Library is developing a pilot departmental Intranet with the open source package, Zope and the Content Management Framework toolkit. The approach is to manage and share content held in a variety of formats, develop workflow for creating and approving new content before it is published to the site, separate content from presentation in order to support easy maintenance and consistency, and locate information through metadata and full text retrieval. Designing the Intranet involved content mapping and identifying library staffâs working needs before developing the structure and site framework. The Zope CMF has proved to be a highly flexible set of tools for creating a knowledge sharing Intranet, but the drawbacks are lack of documentation and training in the UK